Audio Driver API Functions

Audio Driver API functions. More...

Typedefs
typedef void(*	AudioDrv_Event_t) (uint32_t event)
	Audio Events callback function type.

Functions
int32_t	AudioDrv_Initialize (AudioDrv_Event_t cb_event)
	Initialize Audio Interface.
int32_t	AudioDrv_Uninitialize (void)
	De-initialize Audio Interface.
int32_t	AudioDrv_Configure (uint32_t interface, uint32_t channels, uint32_t sample_bits, uint32_t sample_rate)
	Configure Audio Interface.
int32_t	AudioDrv_SetBuf (uint32_t interface, void *buf, uint32_t block_num, uint32_t block_size)
	Set Audio Interface buffer.
int32_t	AudioDrv_Control (uint32_t control)
	Control Audio Interface.
uint32_t	AudioDrv_GetTxCount (void)
	Get transmitted block count.
uint32_t	AudioDrv_GetRxCount (void)
	Get received block count.
AudioDrv_Status_t	AudioDrv_GetStatus (void)
	Get Audio Interface status.

Description

Audio Driver API functions.

Typedef Documentation

AudioDrv_Event_t

AudioDrv_Event_t

Audio Events callback function type.

Parameters

[in]

event

events notification mask

Returns

none

Provides the typedef for the event callback function AudioDrv_Event (uint32 event) to be registered with AudioDrv_Initialize.

The parameter event indicates the reported event(s) that occurred during driver operation. Each event is encoded in a separate bit so it is possible to signal multiple events within the same call. AUDIO_DRV_EVENT_... definitions list the events that can be reported.

Parameter for:

• AudioDrv_Initialize

Function Documentation

AudioDrv_Initialize()

int32_t AudioDrv_Initialize

(

AudioDrv_Event_t

cb_event

)

Initialize Audio Interface.

Parameters

[in]

cb_event

pointer to AudioDrv_Event_t

Returns

return code

The function AudioDrv_Initialize initializes the Audio interface over VSI peripheral. It is called when the middleware component starts operation.

The function performs the following operations:

• Initializes the required resources of the audio interface.
• Registers the AudioDrv_Event_t callback function.

The parameter cb_event is a pointer to the AudioDrv_Event_t callback function; use a NULL pointer when no callback signals are required.

Possible return values:

• AUDIO_DRV_OK : audio interface is successfully initialized.

AudioDrv_Uninitialize()

int32_t AudioDrv_Uninitialize

(

void

)

De-initialize Audio Interface.

Returns

return code

The function AudioDrv_Uninitialize de-initializes the resources of Audio interface.

It is called when the middleware component stops operation and releases the software resources used by the interface.

Possible return values:

• AUDIO_DRV_OK : audio interface is successfully de-initialized.

AudioDrv_Configure()

int32_t AudioDrv_Configure	(	uint32_t	interface,
		uint32_t	channels,
		uint32_t	sample_bits,
		uint32_t	sample_rate
	)

Configure Audio Interface.

Parameters

[in]	interface	audio interface
[in]	channels	number of channels
[in]	sample_bits	sample number of bits (8..32)
[in]	sample_rate	sample rate (samples per second)

Returns

return code

The function AudioDrv_Configure configures audio interface according to specified arguments.

interface configures the audio interface either for input (AUDIO_DRV_INTERFACE_RX) or output (AUDIO_DRV_INTERFACE_TX).

channels, sample_bits, sample_rate define configuration parameters.

Possible return values:

• AUDIO_DRV_OK : configuration completed successfully.
• AUDIO_DRV_ERROR_PARAMETER : invalid argument values. Returned in the following cases:
  • interface is not AUDIO_DRV_INTERFACE_TX or AUDIO_DRV_INTERFACE_TX
  • channel is <0 or >32
  • sample_bits is <8 or >32
  • sample_rate is 0
• AUDIO_DRV_ERROR_UNSUPPORTED : requested configuration is not supported by the driver.
• AUDIO_DRV_ERROR : audio control is already enabled with AudioDrv_Control.

AudioDrv_SetBuf()

int32_t AudioDrv_SetBuf	(	uint32_t	interface,
		void *	buf,
		uint32_t	block_num,
		uint32_t	block_size
	)

Set Audio Interface buffer.

Parameters

[in]	interface	audio interface
[in]	buf	pointer to buffer for audio data
[in]	block_num	number of blocks in buffer (must be 2^n)
[in]	block_size	block size in bytes

Returns

return code

The function AudioDrv_SetBuf assigns DMA buffer to the audio driver interface.

interface specifies whether the buffer is used for input (AUDIO_DRV_INTERFACE_RX) or output (AUDIO_DRV_INTERFACE_TX).

buf points to the memory buffer. block_num and block_size define buffer configuration. Note that the memory allocated for the buffer shall be at least block_num*block_size bytes.

Possible return values:

• AUDIO_DRV_OK : buffer is set correctly.
• AUDIO_DRV_ERROR_PARAMETER : invalid interface value.
• AUDIO_DRV_ERROR_UNSUPPORTED : requested buffer configuration is not supported by the driver.
• AUDIO_DRV_ERROR : returned in the following cases:
  • audio driver is not initialized with AudioDrv_Initialize
  • audio control is already enabled with AudioDrv_Control

AudioDrv_Control()

int32_t AudioDrv_Control

(

uint32_t

control

)

Control Audio Interface.

Parameters

[in]

control

operation

Returns

return code

The function AudioDrv_Control controls the Audio interface.

The parameter control specifies the operation as described in the table.

Parameter control	Bit	Description
AUDIO_DRV_CONTROL_TX_ENABLE. When executed, a timer is configured that periodically sends event to python interface for delivering the audio data.	0	Enable transmit operation.
AUDIO_DRV_CONTROL_RX_ENABLE. When executed, a timer is configured that periodically sends event to python interface for delivering the audio data.	1	Enable receive operation. When executed, a timer is configured that periodically sends event to python interface for retrieving the audio data.
AUDIO_DRV_CONTROL_TX_DISABLE	2	Disable transmit operation.
AUDIO_DRV_CONTROL_RX_DISABLE	3	Disable receive operation.

AudioDrv_GetTxCount()

uint32_t AudioDrv_GetTxCount

(

void

)

Get transmitted block count.

Returns

number of transmitted blocks

The function AudioDrv_GetTxCount returns the number of the currently transmitted data items.

AudioDrv_GetRxCount()

uint32_t AudioDrv_GetRxCount

(

void

)

Get received block count.

Returns

number of received blocks

The function AudioDrv_GetRxCount returns the number of the currently received data items.

AudioDrv_GetStatus()

AudioDrv_Status_t AudioDrv_GetStatus

(

void

)

Get Audio Interface status.

Returns

AudioDrv_Status_t

The function AudioDrv_GetStatus retrieves the current Audio interface status.